docs: def get_analysis_attributes(self, group_name):
          """ Returns the attributes for the specified group or dataset.
          
          :param group_name: The path of the group or dataset, relative to the
              "Analyses" group.
          :returns: A dictionary representing the attributes (if any).
          """
          self.assert_open()
          group = 'Analyses/{}'.format(group_name)
          attr = None
          if group in self.handle:
              attr = self.handle[group].attrs.items()
              attr = {key: _clean(value) for key, value in attr}
          return attr